1. Field of Endeavor
The present invention relates to encapsulation and more particularly to systems for production of polymer encapsulated solids.
2. State of Technology
Systems for producing microcapsules are described in U.S. Pat. No. 7,776,927 and in US. Published Patent Application Nos. 2009/0012187 and 2009/0131543. U.S. Pat. No. 7,776,927 to Liang-Yin Chu et al, assigned to the President and Fellows of Harvard College, discloses emulsions and the production of emulsions, including multiple emulsions and microfluidic systems for producing multiple emulsions. A multiple emulsion generally describes larger droplets that contain one or more smaller droplets therein which, in some cases, can contain even smaller droplets therein, etc. Emulsions, including multiple emulsions, can be formed in certain embodiments with generally precise repeatability, and can be tailored to include any number of inner droplets, in any desired nesting arrangement, within a single outer droplet. In addition, in some aspects of the invention, one or more droplets may be controllably released from a surrounding droplet. U.S. Published Patent Application No. 2009/0012187 to Liang-Yin Chu et al, assigned to the President and Fellows of Harvard College, discloses multiple emulsions, and to methods and apparatuses for making emulsions, and techniques for using the same. A multiple emulsion generally describes larger droplets that contain one or more smaller droplets therein which, in some cases, can contain even smaller droplets therein, etc. Emulsions, including multiple emulsions, can be formed in certain embodiments with generally precise repeatability, and can be tailored to include any number of inner droplets, in any desired nesting arrangement, within a single outer droplet. In addition, in some aspects of the invention, one or more droplets may be controllably released from a surrounding droplet. U.S. Published Patent Application No. 2009/0131543 to David A. Weitz discloses multiple emulsions, and to methods and apparatuses for making multiple emulsions. A multiple emulsion, as used herein, describes larger droplets that contain one or more smaller droplets therein. The larger droplet or droplets may be suspended in a third fluid in some cases. In certain embodiments, emulsion degrees of nesting within the multiple emulsion are possible. For example, an emulsion may contain droplets containing smaller droplets therein, where at least some of the smaller droplets contain even smaller droplets therein, etc. Multiple emulsions can be useful for encapsulating species such as pharmaceutical agents, cells, chemicals, or the like. In some cases, one or more of the droplets (e.g., an inner droplet and/or an outer droplet) can change form, for instance, to become solidified to form a microcapsule, a lipo some, a polymero some, or a colloidosome. As described below, multiple emulsions can be formed in one step in certain embodiments, with generally precise repeatability, and can be tailored to include one, two, three, or more inner droplets within a single outer droplet (which droplets may all be nested in some cases). As used herein, the term “fluid” generally means a material in a liquid or gaseous state. Fluids, however, may also contain solids, such as suspended or colloidal particles. U.S. Pat. No. 7,776,927 and U.S. Published Patent Application Nos. 2009/0012187 and 2009/0131543 are incorporated herein by this reference.